dissenting in part and concurring in part.
I respectfully dissent to the granting of a stay of the district court’s preliminary injunction. The district court did not abuse its discretion when it issued a preliminary injunction against the Navy’s use of MFA sonar during certain planned exercises in the SOCAL range through January 2009.
The Navy has not shown a probability of success on the merits of this case or raised serious questions about the merits. In weighing the possibility of irreparable injury, balancing hardships, and determining where the public interest lies, the district court carefully considered and weighed the national security and public interest issues presented by this case. Until very recently, the Navy employed some environmental mitigation measures it now rejects in the name of national security. Moreover, the Navy has the ability to continue training its personnel in the use of MFA sonar technology pending the outcome of the merits of this case by conducting MFA sonar exercises outside the SOCAL range. In fact, the district court received evidence that the Navy is testing MFA sonar technology “all over the world all the time.” It is the Navy’s sharp starboard tack from its recent training practices that has left it in irons fighting environmental laws, not a failure by the district court to consider national security or the public interest.
On appeal, we review the issuance of a preliminary injunction for abuse of discretion. Ashcroft v. ACLU, 542 U.S. 656, 664, 124 S.Ct. 2783, 159 L.Ed.2d 690 (2004). Under the abuse of discretion standard, a reviewing court cannot reverse absent “a definite and firm conviction that the district court committed a clear error of judgment in the conclusion it reached upon weighing of the relevant factors.” SEC v. Coldicutt, 258 F.3d 939, 941 (9th Cir.2001).
The standard for determining whether to grant a stay pending appeal is similar to that applied by a district court when considering the issuance of a preliminary injunction. Tribal Vill. of Akutan v. Hodel, 859 F.2d 662, 663 (9th Cir.1988). A preliminary injunction may be issued when the moving party demonstrates “either: (1) a likelihood of success on the merits and the possibility of irreparable injury; or (2) that serious questions going to the merits were raised and the balance of hardships tips sharply in [the moving party’s] favor.” Lands Council v. Martin, 479 F.3d 636, 639 (9th Cir.2007) (quoting Clear Channel Outdoor Inc. v. City of Los Angeles, 340 F.3d 810, 813 (9th Cir.2003)).
As noted by the majority, we are also required to consider “where the public in*866terest lies” in certain cases. Hilton v. Braunskill, 481 U.S. 770, 776, 107 S.Ct. 2113, 95 L.Ed.2d 724 (1987); Taylor v. Westly, 488 F.3d 1197, 1200 (9th Cir.2007). I respectfully differ with the majority, however, concerning how the “public interest” consideration applies in this case. Department of Navy v. Egan, 484 U.S. 518, 108 S.Ct. 818, 98 L.Ed.2d 918 (1988), cited by the majority for the proposition that “unless Congress specifically has provided otherwise, courts traditionally have been reluctant to intrude upon the authority of the Executive in military and national security matters,” is distinguishable from the facts of this case. Egan involved the discharge of a Navy employee whose security clearance had been denied; it was not an environmental case. Id. at 522, 108 S.Ct. 818. The Supreme Court held that the authority to classify and control access to information bearing on national security and to determine which individuals have the right to access such information flows from the President’s authority as Commander in Chief and exists apart from any explicit congressional grant. Id. at 527, 108 S.Ct. 818. It also noted a “ ‘compelling interest’ in withholding national security information from unauthorized persons in the course of executive business.” Id. But “public interest” considerations in environmental cases are very different from those in security clearance cases, and the military has long been required to comply with NEPA and numerous other environmental laws, even though national security considerations have been involved. See, e.g., San Luis Obispo Mothers for Peace v. Nuclear Regulatory Commission, 449 F.3d 1016, 1035 (9th Cir.2006), and cases cited therein.
The majority also cites Hilton v. Braunskill, 481 U.S. 770, 107 S.Ct. 2113, 95 L.Ed.2d 724 (1987), for the proposition that even “ ‘failing’ a strong likelihood of success on the merits, the party seeking a stay may be entitled to prevail if it can demonstrate a ‘substantial case on the merits’ and the second and fourth factors militate in its favor.” But Hilton was a habeas corpus case, not an environmental case, and deals with the standards for releasing a prisoner from confinement pending appeal. Id. at 775-76, 107 S.Ct. 2113. The “public interest” considered in Hilton was whether the lower court could properly take the dangerousness of the habeas petitioner into account as part of its decision whether to release the petitioner pending appeal. Id. at 777, 107 S.Ct. 2113. The court concluded that the court may do so, despite the traditional preference for release. Id. at 778, 107 S.Ct. 2113. The “public interest” in this case is very different and constitutes a weighing between the “national security” public interest advocated by the Navy versus the environmental “public interest” advocated by the Appellees. Hilton does not, in my view, permit this court to decline to consider the requirement that the Navy show a probability of success on the merits in order to grant a stay of the district court’s injunction.
1. The Navy fails to meet its burden of showing probability of success on the merits and fails to raise serious questions going to the merits of this case. Although Congress could easily include a national security exemption in the National Environmental Policy Act (“NEPA”), 42 U.S.C. §§ 4321-4347, it has not done so. As we stated in San Luis Obispo Mothers for Peace, 449 F.3d at 1035, “[t]here is no ‘national defense’ exception to NEPA.... The Navy, just like any federal agency, must carry out its NEPA mandate to the fullest extent possible and this mandate includes weighing the environmental costs of the [project] even though the project has serious security implications.” Id. (quoting No GWEN Alliance v. Aldridge, 855 F.2d 1380, 1384 (9th Cir.1988)) (internal quotation marks omitted) (emphasis *867added). The Navy’s Environmental Assessment (“EA”) reports that the planned SOCAL exercises may result in approximately 170,000 “takes” of marine mammals and, according to the district court’s order, may include “approximately 8,000 exposures powerful enough to cause a temporary threshold shift in the affected mammals’ sense of hearing and an additional 466 instances of permanent injury to beaked and ziphiid whales.” Our holding in Blue Mountains Biodiversity Project v. Blackwood, 161 F.3d 1208 (9th Cir.1998), instructs that in order for the plaintiffs to prevail on a claim that the Navy must prepare an Environmental Impact Statement (“EIS”) for the SOCAL exercises, “a plaintiff need not show that significant effects will in fact occur. It is enough for the plaintiff to raise substantial questions whether a project may have a significant effect on the environment.” Id. at 1212 (internal quotation marks and citations omitted). The district court found that the Navy’s EA and other evidence had shown to a “near certainty that the use of MFA sonar during planned SOCAL exercises will cause irreparable harm to the environment and to plaintiffs’ declarants.” Accordingly, it appears at this stage of the proceedings that the Navy will have to prepare an EIS before it engages in its training exercises within the SOCAL area. 42 U.S.C. § 4332(2)(C); Native Ecosystems Council v. United States Forest Serv., 428 F.3d 1233, 1239 (9th Cir.2005). The Navy has not yet prepared an EIS, and it has not yet offered any legally viable defense to the EIS preparation requirement.
Similarly, the Navy failed to submit its sonar activities for a consistency determination to the California Coastal Commission (“CCC”) as required by the Coastal Zone Management Act (“CZMA”), 16 U.S.C. § 1456(c)(1), and then refused to comply with the Commission’s proposed mitigating measures, some of which are the same mitigation measures employed by the Navy from mid-2006 to January of 2007. As with NEPA, the Congress created no national security exemption to the CZMA, and the Navy appears to be in violation of the CZMA. See id. The Navy has not yet offered any legally viable defense to its failure to comply with CZMA.
Accordingly, the Navy has not met its burden of showing probability of success on the merits and fails to raise serious questions going to the merits of this case. The majority does not address this required prong of the test the Navy must meet in order to obtain a stay. Hilton does not apply here, but even if it did, the Navy still cannot meet its burden to show that it has a “substantial case on the merits,” as Hilton requires.
2. The Navy also fails to show that it will suffer irreparable harm if the stay is not granted or that the balance of hardships tips sharply in its favor. It also fails to make the case for a compelling public interest that overrides the Navy’s probable violations of NEPA and CZMA. From mid-2006 to January -of 2007, the Navy used a set of environmental mitigation measures for all MFA sonar exercises other than RIMPAC. It adopted similar measures when it conducted MFA sonar exercises as part of the 2006 RIMPAC near Hawaii, and added additional protections for planned chokepoint and isobath exercises. From mid-2006 to January of 2007, the Navy did not operate MFA sonar within twelve nautical miles of the coast. From mid-2006 to January of 2007, the Navy enlarged the safety zone for marine mammals when certain significant surface ducting conditions existed. From mid-2006 to January of 2007, the Navy followed certain procedures during low visibility conditions, whereby if detection of a marine mammal was not possible out to the prescribed safety zone, the Navy would *868power down sonar if marine mammals were present in the zones it could not use. From mid-2006 to approximately January of 2007, the Navy provided focused monitoring for mammals before, during and after chokepoint exercises.
And yet, commencing some time in early 2007, without providing convincing (or in some cases, any) evidence compelling its change in policy, the Navy has declined to continue employing the referenced environmental mitigation measures it used from mid 2006 to January of 2007, let alone been willing to adopt the further measures sought by the CCC, that would likely have permitted it to conduct exercises in the SOCAL range.
There is no “national security trump card” that allows the Navy to ignore NEPA to achieve other objectives. By declining to write a national security exemption into NEPA, Congress has evidently concluded that it does not jeopardize national security to require the military to comply with NEPA, and the courts have agreed. See e.g., San Luis Obispo Mothers for Peace, 449 F.3d at 1035. Moreover, unless someone can demonstrate that the Navy jeopardized our national security and failed to properly train our involved military personnel by adopting the referenced environmental mitigation measures during the period from mid-2006 to January 2007, it is hard to imagine why implementing some of those same environmental mitigation measures now would do so, especially if doing so would open the possibility of training within the SOCAL range.
3. As further evidence that neither the Navy nor national security will suffer irreparable harm or that the public interest will be harmed by leaving the district court’s preliminary injunction in place pen-dente lite, the Navy has already completed three of its fourteen planned SOCAL exercises scheduled from February 2007 to January 2009. Even more importantly, given the limited language and scope of the injunction, the Navy is free to proceed at any time with its MFA sonar training exercises outside the SOCAL area that are similar to the conditions in the SOCAL area. The majority says this is unpersuasive because the Navy claims “there is no duplicative location where land, sea, undersea and airspace assets are controlled by military authorities that allow full play and training by THIRD Fleet operational actors.” But the district court already considered this contention by the Navy and found as follows at the hearing for the preliminary injunction:
What is not clear from the papers nor was it ever fully addressed in the question of the Hawaii exercises is the fact that this is not the only place in the world where this kind of testing can go on.
There is nothing before me to indicate there are not other places in the world where this testing could go on. And, in fact, in the larger lawsuit, the court has evidence that, in fact, testing is going on all over the world all the time, (emphasis added).
In making these findings, the district court considered the same classified documentation we did, as well as a far more extensive set of documents and studies. We traditionally defer to the findings of the district court concerning matters of fact. This should particularly be true here where much of the counter documentation of the appellees is not before us as it was before the district court.
4. Unlike my colleagues in the majority, I am satisfied that the district court carefully weighed national security and public interest considerations before issuing the preliminary injunction in this case. The record shows that the district court reviewed certain documentation pertaining *869to national security matters in camera pri- or to issuing its injunction. The court transcript also shows clearly that the court carefully considered national security interests before issuing its injunction.
Well, let [me] say it is clear from your papers and from everything that I have read that the MFA active sonar testing is important. It’s critical to national security. I have absolutely no problem with that concept or the reality of it. What is not clear from the papers nor was it ever fully addressed in the question of the Hawaii exercises is the fact that this is not the only place in the world where this kind of testing can go on.
There is nothing before me to indicate there are not other places in the world where this testing could go on. And, in fact, in the larger lawsuit, the court has evidence that, in fact, testing is going on all over the world all the time.
So while I recognize the significance of saying these fourteen exercises cannot be conducted the way they’ve been proposed, which is with little or no mitigation, it does not mean that there ivill be no active MFA sonar testing for our Navy. That’s not the result here.
The issues are tremendously important, and it’s never easy to balance something as significant as safety to wildlife with issues that may hinge on national security and injury or harm to the Navy. I remain satisfied that the plaintiffs have established to a near certainty that the use of MFA sonar during planned SO-CAL exercises will cause irreparable harm to the environment and to plaintiffs’ declarants.
The couri is satisfied the balance of hardships tips in favor of granting the injunction as harm to the environment, plaintiffs, and the public interest outweighs harm to the defendants if they were prevented from using MFA sonar in Southern California during these exercises without effective mitigation measures.
(emphasis added).
In light of the district court’s actions and statements, I find no abuse of discretion merely because the words “national security” do not appear in the district court’s order granting the injunction. I also respectfully note that it is the Navy that has rejected mitigation measures, not the district court or the plaintiffs.
The district court did not abuse its discretion in handing down its preliminary injunction, and I respectfully dissent.
I do concur with the majority that this case should be heard by a merits panel of our court at the earliest possible date. I also concur in the granting of plaintiffs motion to strike the “Unclassified Declaration Addendum of David Yoshihara.”